Change lower unit gears or prop pitch

[BCOMEAUXB]

I have a 1997 Force 120 that I recently blew the lower unit that had 2.07 gears. I had someone graciously give me a lower unit off of a 90 that had 2.33 gears that just needed some seals. I fix the lower unit and got it running good but before at 5250 what was wide open throttle on the other lower unit with a 21" 4 blade I am now turning at 5900 rpm which is way to much for the Force. Should I have the prop reworked to a 22 or 23 for a few hundred bucks or should i spend the $600 dollars and just buy a new set of gears to bring the lower unit back to a 2.07.

 

[Frank Acampora]

Re: Change lower unit gears or prop pitch

Go up 2 pitches on the prop. That should lower your RPM by about 400. Buy a used stainless prop off the auctions. The higher pitch prop turning at a lower speed through the water should actually give more top speed at the same engine RPM.

As far as 5900 RPM, the Force engine block should be fully capable of turning that without damage so don't worry about it for the short term until you get another prop.

 

[jerryjerry05]

Re: Change lower unit gears or prop pitch

Craigslist.or e-bay. Craigslist Florida.treasure coast.There were a couple of drives listed there.Jerry

 

[roscoe]

Re: Change lower unit gears or prop pitch

Run it as is.
That vintage of motor can turn 5900 rpm.
If you are really worried about it, back the throttle off 5%.